Field of the Invention
The present invention relates to a ridge formation method and a ridge formation device, and particularly to a method and a device for forming a ridge by removing impurities by sieve operation performed simultaneously with tilling operation and letting finely-grained soil passing through a sieve mesh and falling onto the ground accumulate on the ground. The present invention is preferable for performing field farming particularly in a field containing impurities.
Description of the Background Art
Conventionally, when the field farming is performed particularly in a field containing impurities, it was necessary to firstly remove impurities such as wood wastes, roots of plants, and stones that are scattered on the field. The transplantation of seedlings in tilled ridges containing impurities leads to problems in transplantation, and has a negative influence on the rooting and growth of the seedlings. It is considered that such tendency is significant particularly in a field of clayey soil. Therefore, conventionally, ridges were formed by operation of four steps in total by firstly removing impurities by sieving manually, secondly performing rough tilling operation using a rotary tiller, thirdly performing finely-grained soil tilling, and fourthly attaching a ridge formation tool immediately after the rotary tiller and exchanging a claw of the rotary tiller to one with a different shape.
As an example of the conventional ridge formation tool, Patent Document 1 discloses a furrower capable of easily shifting tilling operation and furrowing operation by arranging a furrowing body performing furrowing to be foldable. Moreover, the ridging working machine disclosed in Patent Document 2 is provided at the rear part of a tiller and performs ridging operation while advancing with the forward travelling of the tiller. A bottom plate and a leveling plate can be easily connected to an earth removing plate. The kind of a claw of the rotary tiller is disclosed in Patent Document 3.